This invention relates to a paper-cutter having a stationary blade and a movable blade which can be favorably used in a facsimile, a copying machine or the like.
With a conventional type of paper-cutters, a sheet of a paper is cut by moving a movable blade downwardly with respect to the stationary blade. There are several different types of paper-cutters, depending on shapes and moving mechanisms of the movable blade. Namely, there are a rotationable type or a guillotine type.
Among the conventional types of paper-cutters, a rotation/moving method may be the most popular one by which, with forming a movable blade as a circular blade, the movable blade is transferred along a distal edge of a stationary blade while said movable blade being rotated and advanced forwardly. According to a structure of this type of paper-cutters, a distal end of a wire, whose proximal end is connected to the rotationable blade, is wound around a drum and a rotational movement of a rotationable blade is achieved by rotating the drum.
During operating said wire-driven type paper-cutter, the drum may idle and a smooth operation can not be maintained if the wire is slackened. Therefore, a certain magnitude of tension force is needed to be applied to the wire through a spring means in order to prevent the idling. However, there are some problems in reliabilities associated to this type of paper-cutters during a long-term usage, such as an idling of the drum, coming-off of the wire from the drum, or cutting of the wire. These problems are due to an aging-deterioration of a stretched portion of the wire.